Circuit breaker



Sept. 22, 1931. w. w. DASHNER CIRCUIT BREAKER Filed May 31, 1929 Jr/ L m m Haw J Patented Sept. 22, 1931 UNITED STATES 1 WILLIAII w. DASHNEB, F LOGANSPORT, INDIANA, ASSIGNOR To R-B-M MANUFAC- TUBING 00., or LOGANSPOR'I, INDIANA, A CORPORATION or NDIANA PATENT OFFICE CIRCUIT BREAKER Application filed May 31, 1929. Serial No. 367,282.

- This invention relates in general to circuit breakers, more particularly to circuit breakers for the protection of electrical toys.

Electricaltoys such as trains, motors and the like are usually driven by current from the commercial electric light source in the home stepped down through a suitable transformer to the voltage required to operate the device. In the case of a toy electric train, it frequently happens that the engine or cars will jump. the track and establish a low resistance path from the third rail to the other rails of the track. Frequently this path is of such low resistance as to practically constitute a short circuit, and unless an 1 arrangement is provided for disconnecting the source of current, the transformer is liable to beruined and a fire started by this short circuit.

In my copending application, Serial No; 265,310 filed. March 28, 1928, I disclosed a safet device for electrical toys of this kind which comprised in conjunction with the transformer supplyingcurrent to the toy, a circuit breaker or relay designed to open the transformer circuit in case of an overload on the transformer. This relay may 5 be arranged to open the-primary circuit of the transformeror if desired'to open the second ary circuit, 'a-nd the electromagnet of the re ay can be placed either in the primary or secondary circuit of the transformer.

My present invention has for its principal object the provision'of a new and improved circuit breaker of this class, adapted to be inserted in the secondary circuit of the trans former and to open that circuit when the curr ent"in it and' through the circuit breaker becomes abnormally high. 7 V i This improved circuit breaker may be combined with the transformer in the manner indicated inthe above mentioned copending application, or it may be fabricated as an article manufactured to be added to the-electric train sets already inuse. The combinat ion of this relay with the transformer or other source of power for anelectric train or other similar toy renders the toy safe by opening-the circuit to it in case of any fault or condition which causes an abnormally large current to flow through the breaker. I

The circuit breaker built in accordance with the teachings of my present invention is of rugged construction and capable of withstanding the hard usage to which devices of this kind are subjected. Moreover the breaker can be economically manufactured and sold at an attractive price and because of its rugged construction can be expected to withstand abuse and remain in an operative condition over a long period of time.

To acquaint those skilled in the art with the principle of my invention I have illustrated a preferred form of it in the accompanying drawings, in which,

Figure 1 shows a plan view of a completely assembled circuit breaker,

Figure 2 is a plan view of the breaker with the cover partially cut away,

Figure 3 is a cross-sectional view of the breaker taken along the lines 3-3 of Figure 1,

Figure 4 is an end view of Figure 1 with the cover cut away along the lines 4-4 and looking in the direction of the arrows, and

Figure 5 is a circuit diagram showing a use of the circuit breaker.

From the drawings, particularly Figures 2, 3, and 4 it will be seen that the breaker comprises the base plate 1 upon which is mounted the sub-base 2. The sub-base 2 is preferably made of an insulating material such as a phenol condensation product or a fiber. Attached to the sub-base 2 are the L- shaped bracket 11, the z shaped bracket 14, and the C-sha ed bracket 19. These brackets are all pre erably made of magnetic iron, although if desired bracket 19 may be made of any other preferred metal.

The electromagnet 1.0 is attached to the upper end of the L-shaped bracket 11.. This magnet comprises the magnetic iron core 12 around which are placed the customary spool heads to retain the copper wire winding in place on the core. In the preferred embodiment of the invention this winding will be of very low resistance since it will be connectedin series with the circuit extending to, the toy protected by the breaker. Preferably the winding is-of enameled copper wire thismagnetization of the core. 7

although any other preferred form of installation may be used.

The armature 15 is supported at approximately its mid point by the pivot screw 16 which projects through it and the Z-shaped bracket 14. One end of the armature, that is the endadjacent to the electromagnet 10 is equipped with the downward projeeting pole piece 1? which engages the pole piece of the electromagnet lO when the armature is in its energized position.

The magnetic circuit of the armature and electromagnetic extends from the core of the magnet 10 through the air gap into the pole piece 17 of the armature, through the armature and pivot into the bracket 14 and across another air gap disposedbetween the footof the bracket 14 and" the foot of the magnet supportingbracket 11. The air gaps in this magnetic circuit are large and consequently a high magnetization of the core 12 is necessary before sufficient strength will be developed toattract the armature 15, and in the normal operation of the toy the current drawn by it will not be sufficient tov produce The other'end of the armature 15 extends into juxtaposition to the YC-sha'ped bracket 1 9. VA contact spring'18is attached. to the upper portion of this'bracket and extends downward to a point below the plane of the armature 15,and thenupward into engagement with the bottom side of that armature. This spring extends beyondthe vpoint of contact with the armature in a downward direction at an angle as will be best'seen in Figure 4, for a purpose which will be hereinafter pointed out; 1

A projecting lip20 is bent upward from the upper arm of the bracket 19 in a: plane substantially vertical to the sub-base 2. An operating lever 21 is pivoted to this bracket,

7 this lever having a projection'22 which projects through an opening 23 in the armature 15. Through the operation of this lever the circuit through the circuit breaker isreclosed after it has been opened by an overload. The lever- 21 ispreferablymade of an insulating material such as'a phenol condensationproduct'or a fiber to guard against the possibility of the operator receiving a shock from the lever when it is being moved to close thecircuitthrough the breaker.

A metallic box-like cover 8 is attached to the base'plate 1 and serves to enclose the breaker mechanism. This cover is provided with a slot through which the lever 21 eX- tends o permit the operation of that lever to refit the breaker without removing the cover from the breaker. are mounted in the end of the cover and insulated therefrom by the insulators 50.

Preferably the cover is made of sheet ironand formed out of cne'piece in a ferming press. Thecover is finished by lacquer pref Terminal posts 30 and 31" method.

The electrical circuit continues through the bracket 14 and the armature 15 and the 'contact spring 18 to the bracket 19 which is connected by the wire 32' to the other bind ing post 30. It will be noted'that' the electromagnet 10 and the: contacts'15 and 18 are in a series circuit extending through the circuit breaker from binding post.- V r a a Figure 5, illustrates a use of-thecircuit breaker. In this circuit the breaker-is connected-in a series with the secondary circuit of a transformer used'for driving electrical post to binding toysand the like; The primary winding44 of'this transformeris connected tea. commerical lighting circuit which is-usu ally of volts, 60cycle alternating current.- The secondary winding 43. is magnetically: coupledto the'primary winding by 'the core 45 and terminates in the terminals 40' and 41. Theterminal 41 is connected through the variable rider 42 which engages the secondary winding at various points to adjust the voltage in the secondarylcircuit. As shown the terminal 40 of the transformer is con-. 77

nected to terminal 31 of the circuit breaker, the circuit extending through the winding of the magnet 10,. through the armature 15 and the contact? 1-8 to the terminal 30 of the circuit breaker from whence it .go'es'through the electrical toywand returnsv to thetrans former through theterminal 41.

. Assumethe electricaltoy infFigure 5'is an electrical train; while that train is on the track and. runmng' 2 normally the current flowing throughthe secondary circuit will not be sufiiciently strong toiattract the armature 15. It will be notedin Figure 4;,that the spring 18 bears against the under, flat surface of the armature 15, this spring having considerabletension places an appres ciable friction upon" the armature which must be overcome by the electromagnetrbefore the armature can "be moved; As long as the train stays upon the track the current through this circuit will not generate sufli cient' flux in the magnet 10 to overcome this.

friction and attract the armature.

' If however the train goes off the track and thereby short circuits the secondary circuit, the current therein andthrough the electromagnet '10 will'rise to such avalue that the magnetomotive force of the magnet will be sufficiently high to drive a larger amount of flux across the air gaps of the magnetic circuit to overcome the friction of the spring 18 against the armature 15 and to move that I armature into engagement with the pole piece 12.

It will be noted in Figure 4, that the portion of sprin 18 extending beyond the point of contact that sprin with the armature 15 angles downward. hen the magnet attracts the armature and moves it to the left in Figure 4 this angling portion of the spring will bear against the edge of the armature and impart thereto a force tending to move the armature to the left.

By this arrangement the tension of the spring 18 is first made to oppose the movement of the armature and later when that movement has actually started this same tension is employed to assist the movement.

The slope of the spring 18 is such that the tension of it is applied to the armature until the pole piece 17 of the armature is quite close to the pole piece 12 of the electromagnet 10 and since the force of the electromagnet 10 upon the armature pole piece 17 varies inversely as the square of the distance between the two, this force will be high when the tension of the spring is removed from the armature, and the armature will be moving at a high rate of speed. The current will be broken only when the edge of the armature 15 moves out of engagement with the sloping portion of spring 18, and since the armature is moving at a rapid rate when this occurs the breaking of the circuit will not result in an appreciable are even though the current broken is quite large. Moreover by this arrangement the surfaces through which the current is normally conducted are not surfaces through which the current is passing when the circuit is opened, and any arcing which may pit the breaking surface will have no effect upon the normal circuit through the breaker.

When the armature moves to the left as seen in Figure 4, the lever 21 rotates about its pivot and that portion of it extending beyond the cover 3 moves to the right in the slot in the cover. This altered position of the lever 21 serves as a signal or indicator to apprise the operator that the circuit breaker has opened.

After the train has been replaced on the track and it is desired to again supply current to it the lever 21 is moved to the left as seen in Figure 4, to thereby rotate the armature 15in the opposite direction to reestablish the connection between it and the spring 18 to thereby reclose the circuit through the breaker.

From the foregoing it will be apparent that the use of this circuit breaker opens the circuit to an electrical toy'or similar device when the current flowing thereto becomes excessively large and moreover the open tion of the circuit breaker is indicated y a visual'signal. The "device is ruggedly constructed and can be economically made.

"While 'I have chosen to draw a preferred embodiment of my invention, I have done so by way of example only as I'am aware that there are many modifications and adaptations which can be made within the scope'of the invention and I am not therefore to be limited by the specific disclosure made. I Having thuscomplied with the statutes as shown and described a preferred embodiment of myinvention, what I consider new and desire to have protected by Letters Patent, is pointed out in the appended claims.

' What is claimed is: i 1. In a circuit breaker of the class described, an armature, a magnet coil, a pivot about which said armature is moved by an abnormal energiz ation of said magnet coil, a spring engaging said armature, and an angled extension of said spring engaging said armature only during its rotation about its pivot to aid said rotation.

2. In a circuit breaker of the class described, an armature, a magnet coil, a pivot aboutwhich said armature is moved by an abnormal energization of said magnet coil,

a contact spring engaging said armature to establish an electrical circuit through it'and said coil, and an angled extension ofsaid spring engaging said armature only during rotation about its pivot to aid said rotatron. a I

3. In acircuit breaker of the class described, a pivoted armature moved in one direction by an electromagnet, a contact spring normally engaging a flat face of said armature, and an inclined extension of said spring which'engages the edge of said armature while it is being moved by theelectromagnet tocause the tension of said spring to assist in said movement.

4. In a circuit breaker of the class described, a pivoted armature moved in one direction by an electromagnet, a contact spring normally engaging a flat face of said armature, said spring containing an extension shaped to resist movement of said armature until such is started and then to aid that movement.

spring extending downward through an arcuate path then upward into engagement with the under surface of the armature and finally downward from the point of contact with the armature, said final portion bearing an armature pivoted thereon, one leg of said Z- bracket :being' spaced adjacent said L V a I against the edge of the-armatureduri-ng its movement/Vito:aid inthatrmovement. -G.' A circu it breakercomprising,abase, a sub-base,v or insulating material mounted thereon, an, L-shaped magnetic iron bracket attachedto said sub-base, an electromagnet mounted on said bracket, a z-shaped magnetic iron bracket mounted on said sub-base,

bracket to form with said armature a low permeability magnetic path for said electro-.

magnet, andTcontactsclosed and opened by said armature; r v 1,-7.1 A circuit breakercomprising abase, a

sub-base of insulating material mounted thereon, an L-shaped magnetic metal-bracket attached to said sub-base, an electromagnet mounted on'said bracket, aZ-shaped magnetic metal bracket mounted on said sub-base, an armature pivoted thereon, one leg of said Z shaped bracket beingcdisposed adjacent v said L bracket to form'with said armature a 7 low permeability magnetic pathvfor said electromagnet, axC-shaped bracketon said sub-base, a contact spring mounted thereon and cooperating withsaid armature to establish an electrical contact therebetween,

and a levervinounted 0n said-C-bracket and engagingsaid armatureto move it.

8; A circuit breaker or the class described,

comprisingv a base, an insulating sub-base I mounted thereon, a coil, an armature and a contact spring, a separate bracket for mountingeach on said sub-base, said coil and armature bracket with the armature forming a low permeability magnetic-path for said coil, a cover mounted on said base to enclose said breaker, and a lever mounted in juxtaposition to said armature and contact spring and extending through a slot in said cover.

In- Witness" whereof, I hereunto subscribe iny name this 22nd day of May, 1929.

, WILLIAM DAsHNER; 

